Retractable felt tip pen with air seal system
A retractable felt tip pen has a seal system that prevents air from drying out the felt between uses. The seal system can be actuated with one hand, and comprises two sealing devices that may be used in series in the pen or may be used alone. The first sealing device is a flexible self-sealing membrane, and the second is a specially-shaped and hinged cap. The membrane is actuated by extension and retraction of the felt itself. The cap may be actuated either by extension of the felt alone or by the push of a finger on the cap. Replacement of the cap is effected by snapping the cap over the end of the pen, again with one finger.
This patent application is a Continuation-in-Part of application Ser. No. 11/622,155 filed Jan. 11, 2007.
FIELD OF INVENTIONThis invention is in the field of hand-held writing instruments, more specifically those designed for carrying in a pocket, and more specifically those designed for operation with one hand.
BACKGROUND OF INVENTIONThe invention of the felt-tip pen in the late 20th century greatly expanded the versatility of the ink pen by providing a wider line. This greater width made it possible to hand write large characters that could be seen from a greater distance. It also enabled calligraphic writing capability with less attention to ink spillage, as would normally be the case when dipping a fountain pen nib in a bottle of ink, and with better control the application of ink to medium than can be had with a brush. The large ink capacity of felt wicks provided an alternative to the ball point as a disposable pen. The highlighter pen is an extension of the felt tip pen using high transmittance inks.
The chief drawback to felt tip pens is that they dry out quickly if left uncapped. This means that people who would like to utilize the full life of a felt tip pen or highlighter must take care to replace the cap after each use and even during idle periods while using the device. This makes using such a device a two-handed (or one hand plus teeth) operation. A need exists for a means, either self actuating or operable with one hand, to prevent the ink from drying out.
BRIEF DESCRIPTION OF INVENTIONThis invention is a felt tip pen having a retractable tip and a system for sealing the tip against the free flow of ambient air. The air seal system can be actuated with one hand. The air seal system comprises two sealing devices that may be used in series in the pen or may be used alone as separate embodiments. The first sealing device is a flexible self-sealing membrane, and the second is a specially-shaped and hinged cap. The membrane is actuated by extension and retraction of the felt itself. The cap may be actuated either by extension of the felt alone or by the push of a finger. Replacement of the cap is effected by snapping the cap over the end of the pen, again with one finger. A third embodiment provides a resilient foam gasket to further reduce possible air intrusion through the first embodiment. A fourth embodiment is a felt tip pen having two felt tips, one at either end, in combination with one or more of the first three embodiments' air seal system.
The principal object of the invention is, then, to providing a felt tip pen having one or two felt tips, the felt tips being provided with means for extending and retracting them from inside a case and being provided with means for sealing them during non-use against drying out by exposure to the ambient air. Another object of the invention is to provide such means for extending and means for sealing as are operable with one hand while holding the pen.
Referring now to the drawings, in which like elements in each drawing are represented by like reference numerals,
Note that cap 3 has molded into it a button 26 shaped to fit within recess 27 in nose 23. This permits felt tip 5 to push cap 3 open when it is extended.
Hinge or hinges 8 may be reinforced to increase biasing tendency by the embedment of stiffening elements inside them, such as wires (not shown) when the apparatus is molded.
Thus, this invention can take the form of the first embodiment (cap only), the second embodiment (membrane only or membrane combined with cap), or the third embodiment (cap with seal, with or without membrane).
Claims
1. A felt tip pen, comprising:
- an elongate, hollow case having a substantially linear elongate axis, the case further comprising two opposing ends;
- a hole in at least one end;
- at least one felt tip extendable and retractable from the at least one end;
- means for extending and retracting the at least one felt tip with a finger tip;
- a shaped cap fitting over a congruently-shaped nose molded onto said at least one end integrally to said case, with said hole centered on the shaped nose, said hole being substantially perpendicular to and coaxial with said axis;
- the shaped nose shaped according to planar geometric elements having curved peripheries, the planes of the elements being substantially perpendicular to said axis;
- the elements beginning at said hole and progressing along said axis away from said hole toward said opposing end, and having a progression of average diameters at first enlarging and then decreasing until the nose merges into said case;
- the cap being integrally hinged to one side of the nose with at least one flexible hinge and snapping over the enlarged average diameters of the elements of the nose.
2. The felt tip pen of claim 1, in which:
- said cap is attached to said at least one hinge, and said at least one hinge is attached to said one side of said nose, so that when said at least one hinge is in its most unbiased state, said cap is fully open and rests substantially alongside said case.
3. The felt tip pen of claim 2, in which:
- said cap further comprises on its inner surface a button, substantially centered on said hole and extending far enough into said case such that when said at least one felt tip is extended, said felt tip pushes on the button, unsnapping said cap.
4. The felt tip pen of claim 3, in which:
- the outer surface of said cap is shaped to conform to the outer surface of said case when said cap is fully open.
5. The felt tip pen of claim 4, in which:
- the outer surface of said case comprises means for releasably holding said cap against the outer surface of said case.
6. The felt tip pen of claim 5, in which:
- the annular surface of contact between said nose and said cap surrounding said hole further comprises means for sealing said nose against said cap.
7. The felt tip pen of claim 6, in which:
- said means for sealing said nose against said cap comprises a piece of resilient foam.
Type: Grant
Filed: Feb 9, 2007
Date of Patent: Feb 26, 2008
Inventor: Ceylon H. Rentz (Jacksonville, FL)
Primary Examiner: Huyen Le
Attorney: Jonathan Rigdon Smith, P.C.
Application Number: 11/673,141
International Classification: B43K 5/00 (20060101);